<html>
<head>
  <meta charset="utf-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <title>用户登录</title>
  <!-- Bootstrap 核心 CSS 文件 -->
  <link rel="stylesheet" href="//cdn.bootcss.com/bootstrap/3.3.5/css/bootstrap.min.css">
  <style>
    /*web background*/
    .container{
      display:table;
      height:100%;
    }

    .row{
      display: table-cell;
      vertical-align: middle;
    }
    /* centered columns styles */
    .row-centered {
      text-align:center;
    }
    .col-centered {
      display:inline-block;
      float:none;
      text-align:left;
      margin-right:-4px;
    }
  </style>
</head>

<body>
<div class="container">
  <div class="row row-centered">
    <div class="well col-md-6 col-centered">
      <h2>欢迎登录</h2>
      <form:form action="/login" method="post" role="form">
        <div class="input-group input-group-md">
          <span class="input-group-addon" id="sizing-addon1"><i class="glyphicon glyphicon-user" aria-hidden="true"></i></span>
          <input type="text" class="form-control" id="userid" name="userid" placeholder="请输入用户ID"/>
        </div>
        <div class="input-group input-group-md">
          <span class="input-group-addon" id="sizing-addon1"><i class="glyphicon glyphicon-lock"></i></span>
          <input type="password" class="form-control" id="password" name="password" placeholder="请输入密码"/>
        </div>
        <br/>
        <button type="submit" class="btn btn-success btn-block">登录</button>
      </form:form>
    </div>
  </div>
</div>


<!-- jQuery文件。务必在bootstrap.min.js 之前引入 -->
<script src="//cdn.bootcss.com/jquery/1.11.3/jquery.min.js"></script>

<!-- 最新的 Bootstrap 核心 JavaScript 文件 -->
<script src="//cdn.bootcss.com/bootstrap/3.3.5/js/bootstrap.min.js"></script>
</body>
</html>